Technical Focus: How Concrete Moisture Testing Can Help You
Today, one of the fastest-growing trends in the construction industry is to “go green.” People increasingly like knowing that their choices will make a difference when it comes to concerns about climate change, air and water quality, and the conservation of energy and natural resources.
Because many factors must be considered in creating a building that is truly eco-friendly, how can one know that a specific structure fits the standard of being green? How do we determine if it is energy efficient? To what extent were eco-certified products used? Is the space designed to minimize indoor air pollution? What steps were taken to reduce waste and conserve resources during construction? Answers to these types of questions are not always obvious.
Benefits of LEED certification
For this reason, green building standards and certification systems can be extremely useful to buyers, sellers, designers, building contractors, and users of commercial and residential structures.
LEED, or Leadership in Energy and Environmental Design, is perhaps the most respected green building rating system in the world. First established in 1998 by the U.S Green Building Council, LEED is now utilized worldwide in 165 countries and territories and in all types of building projects.1 In the U.S., another prominent certification choice for both commercial and residential construction is the Environmental Protection Agency’s Energy Star® program.2
A LEED-certified building invariably commands a higher resale value, as well as other benefits for the occupants and the local community. These benefits can include instant recognition as a leader in green building design and construction, faster lease-up rates, healthier indoor space, and less use of energy, water and other resources.
LEED certification utilizes a multi-faceted rating system for earning points in several different categories such as sustainable sites, water efficiency, energy and atmosphere, materials and resources, and indoor environmental quality. In a nutshell, score enough points and your building project can earn LEED certification.3
Pay attention to the waste stream
Let’s say you want to incorporate tile flooring as an attractive feature in a building project that is seeking LEED certification. What can you do to help ensure that the flooring aspect of the project does not in any way jeopardize the points needed for certification?
One significant facet of LEED certification and going green is to be conscious of the amount of waste that’s generated. In many ways, waste is the bane of the construction industry. Waste on a typical construction project is estimated to be as much as 30% of the total weight of the building materials delivered to the site.4
What about flooring failures? When they occur, as they sometimes do, they only add to the waste stream stemming from a construction project. Going green should include paying attention to the risk factors that might contribute to a catastrophic flooring failure.
Without a doubt, excessive moisture is the most common cause of flooring failures, and it can happen with tile flooring, too. Neglecting to take the steps needed to avoid a moisture-related flooring failure and you may find yourself adding to the project’s construction waste. Hardly an effective way to go green.
Indeed, LEED’s materials and resources category addresses construction and demolition waste management very specifically. Possible ways to earn points in this category include keeping construction waste to no more than 2.5 pounds per square foot or diverting at least 50% of generated waste from landfills.5
The key step in preventing flooring failure
What can you do to prevent a moisture-related failure? When tile flooring is to be installed over a concrete slab, keep in mind that concrete can hold a substantial amount of moisture. Water is an essential ingredient for ensuring that concrete cures properly and attains the strength, hardness and durability that makes it so valued in construction.
While concrete moisture will always be there, too much of a good thing can become a big problem. Concrete subflooring must dry to an acceptable level; otherwise, the flooring installation may fail. For this reason, the critically important step for preventing flooring failure is to properly assess the concrete’s moisture condition before proceeding with the finished floor installation.
An eyeball assessment of the slab’s surface moisture won’t do. Nor is it enough to take surface-type measurements such as with a handheld meter or by using the anhydrous calcium chloride test. Moisture levels at the surface are not a very useful indicator of the overall moisture condition of the slab. This is because, as a slab dries, moisture typically exists in a gradient, with less moisture near the surface than deeper down. It’s this hidden moisture deep inside the slab that can especially wreak havoc with the finished floor after installation.
Accurate concrete moisture measurement is key
Science has proven that the most reliable indication of the moisture condition of a concrete slab when flooring is installed is a moisture measurement tool that assesses moisture inside the concrete slab.6 Accordingly, the American Society for Testing and Materials (ASTM) has created a standard known as ASTM F2170, which provides guidance on the correct tools and procedures for determining the relative humidity (moisture condition) of a concrete slab using in situ probes. An example of a test that aligns with ASTM F2170 is the Rapid RH L6, which features probes that store time-stamped readings that can be downloaded and stored within a smart device app. Visit ASTM.org for more information on the F2170 in situ concrete slab testing standard.
Flooring failure can contribute dramatically to the amount of waste materials generated by a construction project. Regardless of whether your project is seeking green certification, it is always a good idea to do what you can to ensure the concrete slab will be within flooring manufacturers’ specification for moisture condition at the time you install the flooring material. In situ RH probe tests that align with ASTM F2170 are going to be your best choice for getting the accurate readings you need to make that important business decision to install the flooring.
- Green Building Leadership is LEED. https://new.usgbc.org/leed
- Vierra, Stephanie. Green Building Standards and Certification Systems. https://www.wbdg.org/resources/green-building-standards-and-certification-systems
- What is LEED? – Introduction. https://greenbuildingelements.com/2014/08/21/leed-introduction
- Construction Waste. https://www.sciencedirect.com/topics/earth-and-planetary-sciences/construction-waste
- Construction and Demolition Waste Management. https://www.usgbc.org/credits/new-construction-commercial-interiors-core-shell-schools-nc-retail-nc-retail-ci-healthcare-0
- Spangler, Jason. Discoveries in Science-Based Concrete Moisture Testing. https://www.wagnermeters.com/concrete-moisture-test/concrete-info/science-discoveries-in-concrete-moisture-testing